Experiments were conducted at Monash University in a
3 m × 5 m controlled temperature laboratory (27 °C and
30 % relative humidity; SPER-Scientific Hygrometer, Arizona, USA) to allow effective foraging activity (Norgate
et al. 2010). Bees from a colony propagated by Dr. Tim
Heard following established protocols (Heard 1988) were
housed in a 28 cm × 20 cm × 31 cm (LWH) pine nesting box. The colony was connected to a foraging arena
(1.2 m × 0.6 m × 0.5 m LWH) by a 16 cm Plexiglas tube,
which contained gates to control the movements of bees
(Fig. 3). Pollen grains were provided directly to the nest
box. Illumination (10/14 h day/night) was provided by four
Philips Master TLS HE slimline 28 W/865 UV + daylight fluorescent tubes (Philips, Holland) with specially
fitted high-frequency (1200 Hz) ATEC Jupiter EGF
PMD2614–35 electronic dimmable ballasts and diffused
by Rosco 216 (Germany) UV transmitting screen (spectra
shown in Farnier et al. 2015), providing a constant intensity of 60 μmol m−2 s−1 (∼5180 lx; Fieldscout Quantum
light meter, Spectrum Technologies, Inc., USA) which is
well above intensity levels (0.1–79 lx) that are required for
vision in stingless bees (Streinzer et al. 2016). The arena
had a UV transmitting plexiglass cover. At the far end tothe nest box, a small portal in the arena allowed bees to
fly into a custom Y-shaped maze (Fig. 3). The Y-Maze is
a standard apparatus for testing bee visual acuity (Giurfa
et al. 1996; Dyer et al. 2008). For working with stingless
bees, we constructed a special small Y-Maze, where each
arm measured 30 cm × 10 cm × 10 cm (LWH) and the
back walls were 10 cm × 10 cm.